Permanent Incisor Morphology Flashcards
Arch Traits
Traits that distinguish between maxillary and mandibular teeth
Set Traits
Traits that distinguish between primary and permanent dentition
Class Traits
traits that distinguish between classes of teeth, incisors, canines,
premolars, molars
Type Traits
traits that distinguish between the types of teeth in the same class
Maxillary Central Incisor: General Characteristics
Development
- Calcification – begins around 3 months
- Eruption - 7- 8 years
- Root completion – 10 years
- Lobe development – 4 lobes
- Replaces E, F
B. Naming Maxillary Central Incisors
Universal - #8, #9 FDI – 11, 21
Palmer - 1 1
C. Arch position
1. Adjacent to midline, very prominent
2. Mesial contacts each other, distal contacts the lateral incisors
D. General form
1. Trapezoidal from facial or lingual, triangular from proximal
2. Widest tooth mesiodistally of any of the anterior teeth
3. Largest and most prominent incisor
Maxillary Central Incisor: Crown outline form
trapezoidal
1. Longer incisally, shorter cervically
2. Longer inciso-cervically, than it is wide mesiodistally
Maxillary Central Incisor: Height of contour
cervical 1/3rd, rest is flat
1. Height of contour, contact area important in re-contouring &
replacement of teeth for esthetics and health
Maxillary Central Incisor: Mesial outline form
- Almost straight
- Mesial Incisal angle is sharp
Maxillary Central Incisor: Distal outline form
- More convex or rounded
- Distal Incisal angle more rounded than the mesial incisal angle
Maxillary Central Incisor: Incisal outline
- Can have 3 rounded protuberances called mamelons
- Wear occurs on the lingual
Maxillary Central Incisor: Developmental depressions, grooves, lines
- Vertical faint lines extending from incisal edge fading out at the
cervical
Maxillary Central Incisor: Imbrication lines
- Faint, curved lines running mesial to distal in the cervical 1/3rd-
- Surface manifestations of Stripes of Retzius as enamel is laid down
Maxillary Central Incisor: Contact area
- Mesial Proximal Contact - incisal 1/3
- Distal Proximal Contact - junction of incisal 1/3 and middle 1/3
Maxillary Central Incisor: Lingual fossa
shallow concavity on the lingual surface
Maxillary Central Incisor: Four borders
a. Cingulum - convexity in the cervical 3rd, represents the lingual
developmental lobe
b. MMR - mesial marginal ridge - nearly straight
c. DMR - distal marginal ridge - convexity (curved)
d. Incisal edge
Maxillary Central Incisor: Lingual pit
Sometimes present between the fossa and cingulum
Maxillary Central Incisor: Mesial View/ Distal View
A. Shape – triangular
B. The long axis of the tooth (Facial-Lingual root bisector) passes through the
incisal edge - long axis
C. Height of Contour - facial and lingual - cervical 1/3
D. Incisal wear - on the lingual, slopes lingually
E. Distal contour is more convex (rounded) than the mesial contour
F. Cervical curvature is greater on the mesial than any other tooth in the mouth
Maxillary Central Incisor: Incisal View
A. Crown Outline Form – Shape - triangular
B. Incisal wears on the lingual
Maxillary Central Incisor: Root
A. Single, conical, relatively straight
B. Length - 2-3 mm greater than crown
C. Slight mesial inclination
D. 1 root canal, located in the center of the tooth
a. Shape mirrors the configuration of the tooth
E. Pulp Horns - 3 pulp horns - mesial, distal, central (smaller and more rounded)
F. Root is narrower lingually than facially
Maxillary Central Incisor: Clinical Considerations
Root harder to scale from the lingual
1. Narrow root from lingual
2. Indirect vision
B. Appearance
1. Spaces between teeth
2. Enamel formation - possible defects
3. Color can vary
4. Size can vary
Maxillary Lateral Incisor: General Characteristics
Development
1. Calcification - begins around 1 year
2. Eruption - 8-9 years
3. Root completion - 11 years
4. Lobe development - 4 lobes
5. Replaces D, G
B. Naming Maxillary Lateral Incisors
Universal - #7, #10 FDI – 12, 22
Palmer - 2 2
C. Arch position
1. Second from midline
2. Mesial contacts the central, distal contacts the canine
D. General form
1. Resembles central incisor but smaller - more delicate & slender, except root length
2. More rounded than central incisor, curvatures, convexities, concavities are more prominent
3. Variations are more frequent than any other permanent except 3rd
molars
a. Peg laterals
b. Can be congenitally missing